Method of making epoxide-lignin resins

ABSTRACT

A process for making lignin-epoxide resins from lignin separated from the waste cooking liquor from a paper pulping process comprising the steps of reacting the separated lignin with a chemical system to produce unsaturated end groups on the lignin molecule which are epoxidized to produce the resin.

This invention relates to the separation of lignin from waste blackcooking liquor resulting from the kraft and sulfite paper pulpingprocess and the preparation of useful organic materials from the lignin.The useful organic materials include plastics, adhesives and resins foruse, for example, in paints.

The kraft process broadly relates to the separation of wood intocellulose and lignin. Other materials are separated, for example sugars,hemicelluloses, tall oil, and other chemicals. The separation iseffected essentially by cutting the wood into small portions and thencooking them under heat and pressure with certain pulping chemicalswhich include sodium hydroxide and sodium sulfide. This cooking rendersthe lignin, sugars and hemicellulose materials soluble and these formthe major materials present in the waste black liquor. There are, ofcourse, other chemicals present as well as dissolved pulping chemicals.Normal procedure in a kraft plant is to evaporate the black liquor to agiven solids content which solids are then burned in a furnace torecover the inorganic pulping chemicals which are recycled to producemore pulp. The cellulose is insoluble in the black liquor and isseparated therefrom and made into paper. The only value obtained fromthe lignin in this just mentioned procedure is the heat value derived inthe furnace. The sulfite process is well known to those skilled in theart.

The present invention basically involves the separation or extraction oflignin from waste black pulping liquor. The lignin may be used for manypurposes and one use is to chemically place reactive unsaturatedcarbonyl groups or unsaturated nitrogen-containing compounds on thelignin molecule in addition to the unsaturated groups already naturallyexisting on the lignin molecule and thereafter produce an epoxide-ligninresin by reaction with another chemical, for example hydrogen peroxide.The epoxide-lignin resin may be cured to a hard infusible plastic bymeans of heat and/or a catalyst, it may be reacted with various fattyacids to produce resins for paints and inks or it may be reacted withvarious amines to produce polyamines or polyamides for use as adhesivesor plastics. The aqueous phase of the waste black liquor from which thelignin is separated may be recycled in the normal way to recover thepulping chemicals.

The present invention provides a new and inexpensive source of epoxideresins and the ultimate products therefrom, at a time when the nationalpetroleum supply is being acutely diminished. The supply of lignin fromthe paper industry measures in the millions of tons annually and asmentioned above, the bulk of this lignin is used for its heat valuewhich is acquired by burning. The lignin source is essentially renewedeach year by the tree planting policies of the major paper companies.Some of the strongest adhesives and plastics with excellent mechanicalproperties are epoxy-type adhesives and epoxy-type plastics.

Even though there are on the order of 160 million pounds of epoxy resinsbeing used annually in the United States, the largest volume marketshave been virtually untouched because of the present high cost of theseresins. The present invention will drastically reduce the cost ofepoxy-type resins so they can economically compete for the yet untouchedmarkets.

The lignin separation portion of the present invention is highly usefulin and of itself since it provides an economical method for acquiring anexcellent grade of lignin from both kraft and sulfite black liquor.

The present prior art teaches that lignin in kraft black liquor may beprecipitated and then filtered. Because of the fine colloidal nature ofprecipitated lignin the filtration of lignin becomes a difficultprocedure. Because of this procedure lignin is fused during processingand the liqnin formed is a frit-like material. Unfortunately thisfrit-like lignin material is very difficult to dissolve in solvents andother organic media. These frit-like lignins can be reprocessed to makethem more usable, but the extra processing makes the cost of the lignintoo expensive for large market application.

The present invention enables lignin to be obtained from kraft blackliquor in a fine powder or dissolved in an organic medium which then canbe readily dissolved in various solvents and organic media. Thissolubility characteristic enables the lignin produced from the inventionto be utilized in large market applications. One significant advantageof the invention is that polyols can be used as the solvent or organicmedium for the separation of lignin from kraft black liquor or sulfitewaste liquor. In this way lignin can be effectively utilized in manypolyurethane applications, because by using the lignin in conjunctionwith the polyol, the cost of the polyurethane product is significantlyreduced.

In this invention relating to the separation of lignin from black liquorthere are three distinct aspects, one aspect is where the lignin issoluble in the solvent or organic chemical medium that is used in theseparation. As the solubility of the lignin in the aqueous phase isreduced, the lignin has more affinity for the solvent phase than theaqueous phase and a separation results. In this situation the preferredprocedure is to reduce the solubility of the lignin in the aqueousphase. The reduction of the solubility of the lignin in the aqueousphase may not be necessary if the lignin is significantly soluble in thesolvent or organic chemical medium. The description of this technologyis demonstrated in examples 1 through 25 of the specification.

In the second approach of the separation invention, the lignin hasnormally only partial solubility in the solvent or organic chemicalmedium. In this case, as the solubility of lignin in the aqueous phaseis descreased, the lignin, because of its partial solubility in thesolvent or organic chemical medium, has more affinity for the solventphase than the aqueous phase and a separation results. The descriptionof this technology is demonstrated in examples 68 through 74 of thespecification.

In the third approach of the invention, the lignin is considered to haveno solubility in the solvent or chemical medium. In this case, as thesolubility of the lignin is decreased in the aqueous phase, the ligninbecomes dispersed in the solvent or chemical medium. This dispersion ofthe lignin can be improved through mechanical means. The dispersion ofthe lignin is achieved even though the lignin is not soluble in thesolvent or chemical medium, by the fact that the surface of the ligninparticles is wetted by the solvent or chemical medium. Once the ligninparticle is wetted, the lignin particles are prevented from formingaggregates. Thus the lignin is suspended in the solvent or chemicalmedium. The wetting of the lignin particles is enhanced by suchmechanical means as agitation and conventional dispersing equipment.These lignin particles are formed when the solubility of the lignin inthe aqueous phase is decreased to the point where the lignin is nolonger soluble and precipitates out. Another significant advantage ofthe invention is that of using fluorocarbons which are "Freon" type ofmaterials for the separation of lignin from kraft black liquor andsulfite waste liquor. These fluorocarbons are low boiling pointmaterials which means that significantly less energy is required tospray dry the lignin from these materials. Also these fluorocarbons arenonflammable which means that safety is also significantly improved.These materials are also relatively non-toxic which also improvessafety. The fluorocarbons are also inert so they can easily be recoveredafter spray drying and used again. The description of this technology isdemonstrated in examples 75 through 79 of the specification.

The lignin from sulfite waste liquor is presently obtained by spraydrying the waste sulfite liquor. The final product contains lignin, andalso wood sugars, hemicelluloses and water soluble inorganic salts.These water soluble materials severely limit the potential applicationsthat lignin from sulfite waste find. This invention is also applicableto sulfite waste liquor and this technology is demonstrated in examples80 through 85 of the specification.

Other objects and a fuller understanding of this invention may be had byreferring to the following description and claims, taken in conjunctionwith the accompanying drawings, in which:

FIG. 1 is a flow sheet showing the various steps involved in theteachings of the present invention.

As seen in the flow sheet of FIG. 1 and as discussed above, the firstprocedure involved in the present invention is the separation orextraction of the lignin from the waste black liquor resulting from thekraft paper pulping process. The first twenty-five examples (numberedExamples 1 through 25) illustrate this separation by the use of ketones,esters, aldehydes and ethers. Solids content of the black illustrated is20% and 50%; however, other solids content may be utilized. The examplesalso illustrate that the separation may take place in acid or basicmedia. The specific ketones demonstrated are mesityl oxide,cyclohexanone, isophorone, and methy heptyl ketone; esters are 2, 2butoxy ethoxy ethyl acetate, hexyl acetate, heptyl acetate, amylacetate, iso-amyl acetate and phenyl acetate; aldehydes arebenzaldehyde, valeradehyde, butyraldehyde and furfural; and ethers maybe butyl ether and 2, 2 butoxy ethoxy ethyl acetate in addition to beingan ester, is also an ether.

EXAMPLE 1

This example illustrates the extraction of lignin from kraft blackliquor into an organic solvent. The pH of the black liquor may be on theorder of 12 or 13.

PROCEDURE: Charge 4000 ml. (4 parts) kraft black liquor (50% solids)into a 5-gallon vessel with some means of agitation. Then added 1000 ml.of water (1 part) and stir. Then add 700 ml. (0.7 part) of mesityl oxide(solvent) and stir. While the mixture is being stirred, add 250 ml.(0.25 part) of 80% acetic acid slowly over 10 minutes and stir foranother 10 minutes. The mixture starts to thicken and then thins outagain. At this time add another 300 ml. (0.3 part) of 80% acetic aciduntil the mixture is acidic. The amount of acid required may varybecause alkalinity of the kraft pulps may also vary. The mixture isstirred for 10 minutes and the agitation is then stopped. The mixture isthen allowed to stand and at the end of four hours there is alignin-solvent layer on top which produces 908 gms. of lignin.

EXAMPLE 2

This example illustrates the extraction of lignin from kraft blackliquor into an organic solvent, and the use of an ion (magnesiumsulfate) to reduce soap formation and thus improve the extraction.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor (50% solids)into a 5-gallon vessel. Then add 1400 ml. (1.4 parts) of water and stir.Then add 1400 ml. (1.4 parts) of mesityl oxide and stir. Premix 40 gms.(0.04 part) of magnesium sulfate in 200 ml. (0.2 part) water underagitation over 10 minutes. Add 450 ml. (0.45 part) of 80% acetic acidslowly while agitating the mixture. This addition requires about 15minutes. Stir for 10 minutes and stop the agitation and allow themixture to stand. At the end of four hours there is a lignin-solventlayer formed which produces 950 gms. of lignin.

EXAMPLE 3

This example illustrates the extraction of lignin from kraft blackliquor which contains 20% solids.

PROCEDURE: Charge 8000 ml. (8 parts) of kraft liquor into a 5-gallonvessel. Then add 2400 ml. (24 parts) of water and stir. Then add 5000gms. (5 parts) of mesityl oxide and stir. Then add 600 ml. (0.6 part) of80% acetic acid over a 15-minute interval while the mixture is underagitation. Then stir for another 15 minutes. The agitation is stoppedand the mixture allowed to stand for the fomation of a lignin-solventlayer.

This layer produces 700 gms. of lignin.

EXAMPLE 4

This example illustrates the extraction of lignin from kraft blackliquor which contains 20% solids.

PROCEDURE: Charge 4000 ml. (4 parts) black liquor (20% solids) into a5-gallon vessel with some means of agitation. Then charge 2000 ml. (2parts) of water and stir. Then add 1400 ml. (1.4 parts) of mesityl oxideand stir. Then slowly add 375 ml. (0.375 part) of 80% acetic acid over a15-minute interval. The mixture is then stirred for an additional 15minutes and allowed to stand with no agitation. A lignin-solvent layerstarts to form and is complete within a few hours. This layer producesapproximately 350 gms. of lignin.

EXAMPLE 5

The example illustrates the extraction of lignin from kraft black liquorwhich contains 20% solids with an organic solvent.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor into a5-gallon vessel provided with some means of agitation. Then add 1000 ml.(1 part) water and stir. To this mixture is then added 2000 ml. (2parts) of mesityl oxide and stirred for 5 minutes. Then 350 ml. (0.35part) of 80% acetic acid is added slowly over a 15-minute interval,until the mixture is acidic. The addition of acid is stopped if themixture starts to foam due to the evolution of gases. The mixture isstirred for 15 minutes and the agitation stopped. When the mixture isacidic, it normally will have a light brown color. The lignin-solventlayer which separates produces approximately 350 gms. of lignin.

EXAMPLE 6

This example illustrates the separation of lignin from kraft blackliquor by using a solvent such as methylene chloride which is achlorinated hydrocarbon.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100 ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of methylene chloride. While this mixture is beingstirred, add 25 ml. (0.25 parts) of 80% acetic acid slowly over a fiveminute interval. As soon as the viscosity of the mixture starts toincrease the stirring may be discontinued and a layer starts to formwhich contains the lignin.

The pH of the solution in Examples 1 through 6 is normally kept between4.5 and 6.5. These separations were all carried out at about roomtemperature or slightly lower.

EXAMPLE 7

This example illustrates the extraction of lignin from kraft blackliquor into an organic solvent by reducing the pH but still maintaininga basic solution.

PROCEDURE: Charge 4000 ml. kraft black liquor (50% solids) into a5-gallon vessel with some means of agitation. Then add 400 ml. (4 parts)of water and stir. Then add 1400 ml. (1.4 parts) of mesityl oxide andstir for 5 minutes. While the mixture is being stirred, 300 ml. (0.3part) of 80% acetic acid is added slowly over 15 minutes until the pH ofthe mixture is still alkaline, between about 7.5 and 8.5. The mixture isthen stirred for an additional 15 minutes, and the agitation stopped andthe vessel covered. A lignin-containing layer separates which containsabout 670 gms. of lignin.

EXAMPLE 8

This example illustrates the extraction of lignin from kraft blackliquor into an organic solvent by acidifying with a mineral acid.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor (50% solids)into a 5-gallon vessel equipped with some means of agitation. Then add4000 ml. (4 parts) of water and stir. Then add 2000 ml. (2 parts) ofmesityl oxide and stir for 5 minutes. Premix 150 ml. (0.15 part) ofconcentrated sulfuric acid into 1000 ml. (1 part) of water. Then addthis sulfuric acid solution slowly over 15 minutes while the mixture isunder agitation. When the color of the mixture becomes a light brown themixture is then acidic and the addition of acid is stopped when the pHis in the range of 5 to 6.5 pH units. The agitation is continued for anadditional 15 minutes and then stopped. The 5-gallon vessel is thencovered. The lignin layer contains 813 gms. of lignin.

EXAMPLE 9

This example illustrates the extraction of lignin from kraft blackliquor into an organic solvent by acidifying with a gas that produces anacid in an aqueous solution.

PROCEDURE: Charge 4000 ml. (4 parts) kraft black liquor (50% solids)into a 5-gallon vessel equipped with some means of agitation. Then add4000 ml. (4 parts) of water and stir. Then add 2000 ml. (2 parts) ofmesityl oxide and stir for 5 minutes. While the mixture is underagitation, carbon dioxide gas is passed through a glass frit or bubblerimmersed near the bottom of the mixture. The use of carbon dioxide gasis continued until the mixture is acidic (pH of less than 7.0). The rateis maintained so that no frothing occurs while the mixture is underagitation. After the mixture is acidic the carbon dioxide gas isdiscontinued and the mixture stirred for an additional 15 minutes. Theagitation is stopped and the mixture covered. The solvent-lignin layerproduces 711 gms. of lignin.

EXAMPLE 10

This example illustrates the extraction of lignin from kraft blackliquor into an organic solvent by reducing the alkalinity but stillmaintaining a basic solution, with carbon dioxide gas.

PROCEDURE: Charge 4000 ml. (4 parts) kraft black liquor (50% solids)into a 5-gallon vessel equipped with some means of agitation. Then add400 ml. (4 parts) water and stir. Next add 2000 ml. (2 parts) of mesityloxide and stir for 5 minutes. While the mixture is under agitation,carbon dioxide gas is passed through a glass frit or bubbler which isimmersed at the bottom of the 5-gallon vessel. The rate is adjusted sothat no frothing occurs while the mixture is being agitated. When the pHof the mixture is in the range 7 to 8.9 pH units, the carbon dioxide gasmay be discontinued, however, the closer to an acid pH the better theyields will be. After the carbon dioxide gas is discontinued, themixture is stirred for an additional 15 minutes. The agitation is thenstopped and the vessel covered. The lignin layer produces 665 gms. oflignin.

EXAMPLE 11

This example illustrates the extraction of lignin from kraft blackliquor into an organic solvent by reducing the alkalinity of the blackliquor with a mineral acid but still maintaining a pH of 7 or greater.p0 PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor (50%solids) into a 5-gallon vessel equipped with some means of agitation.Then add 4000 ml. (4 parts) of water and stir. Next add 2000 ml. (2parts) of mesityl oxide and stir for 5 minutes. Premix 100 ml. (0.1part) of concentrated sulfuric acid into 1000 ml. (1 part) of water.This sulfuric acid solution is then added slowly to the mixture underagitation over a 15-minute period. The amount of acid needed will vary,because of the varying amounts of base present in kraft pulps.Therefore, the addition of acid is stopped when the desired pH isreached. In this example a pH of 7.5 to 8.0 was sufficient. After theacid has been added, the mixture is stirred for an additional 15minutes. Then the agitation is stopped and the vessel covered. Thelignin layer produces 710 gms. of lignin.

EXAMPLE 12

This example illustrates the extraction of lignin from kraft blackliquor into the organic solvent methyl heptyl ketone by acidifying thesolution.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor (50% solids)into a 5-gallon vessel equipped with some means of agitation. Then add2000 ml. (2 parts) of water and stir. Next add 4000 ml. (4 parts) ofmethyl heptyl ketone and stir for 5 minutes. Then slowly add 550 ml.(0.55 part) of 80% acetic acid over a 15-minute interval while themixture is being stirred. When the mixture is acidic (pH 5.5 to 6.0) theaddition of acid is discontinued and the mixture stirred for anadditional 15 minutes. When the agitation has stopped, the vessel iscovered. The lignin layer produces 578 gms. of lignin.

EXAMPLE 13

This example illustrates the extraction of lignin into the organicsolvent 2, 2, butoxy, ethoxy, ethyl acetate, from kraft black liquor.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor (50% solids)into a 5-gallon vessel equipped with some means of agitation. Then add4000 ml. (4 parts) of water and stir. Next add 4000 ml. (4 parts) of 2,2, butoxy, ethoxy, ethyl acetate and stir for 5 minutes. Then slowly add550 ml. (0.55 part) of 80% acetic acid over a 15-minute interval whilethe mixture is being agitated. Once the mixture is acidic (pH 5.5 to 6)the addition of acid is discontinued and the mixture is stirred for anadditional 15 minutes. After the agitation has stopped, the vessel isthen covered and a layer will start to form. The lignin layer produces435 gms. of lignin.

EXAMPLE 14

This example illustrates the extraction or separation of lignin fromkraft black liquor into the organic solvent benzaldehyde.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor (50% solids)into a 5-gallon vessel equipped with some means of agitation. Then add1000 ml. (1 part) of water and stir. Next add 5000 ml. (5 parts) ofbenzaldehyde and stir for 5 minutes. Then slowly add 550 ml. (0.55 part)of 80% acetic acid over a 15-minute interval until the mixture is weaklyacidic (pH 5.5 to 6). Then the addition of acid is discontinued and themixture stirred for an additional 10 minutes. After the agitation hasstopped, the vessel is then covered. Because of the density ofbenzaldehyde, the layer containing lignin may not rise to the top, sincethe density of the benzaldehyde lignin layer may be greater than thedensity of the aqueous mixture. The lignin layer produces 756 gms. oflignin.

EXAMPLE 15

This example illustrates the extraction of lignin from kraft blackliquor into a combination of organic solvents, such as xylenes andfurfural. In order to achieve the optimum extraction or separation, itmay be advantageous to combine various solvents to obtain improvedresults.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor (50% solids)into a 5-gallon vessel. Then add 2000 ml. (2 parts) of water and stir.Premix 2000 ml. (2 parts) of furfural and 2000 ml. (2 parts) of xyleneand then add this premix and stir for 10 minutes. Next slowly add 550ml. (0.55 part) of 80% acetic acid to the mixture over a 15-minuteinterval. Once the mixture has become acidic (preferably in the pH range5.0 to 6.5), the addition of acid is stopped and the mixture is stirredfor an additional 15 minutes. Then agitation is stopped and the vesselcovered. The formation of a layer will be complete in 4 to 5 hours. Thelignin layer produces 465 gms. of lignin. The xylene in this exampleacts as a carrier or extender for the furfural and improves theextraction economics. The xylene used was a commercial grade whichcontained m-xylene, o-xylene, p-xylene and ethyl benzene. Toluene andbenzene might also be used as a carrier or extender.

EXAMPLE 16

This example illustrates the separation of lignin from kraft blackliquor by using mesityl oxide with a mixture of xylenes while reducingthe alkalinity of the solution but still maintaining a basic pH.

PROCEDURE: Charge 8000 ml. (8 parts) of kraft black liquor (50% solids)into a 5-gallon vessel equipped with some means of agitation. Then add4000 ml. (4 parts) of water and stir. Then premix 200 ml. (0.2 part) ofmesityl oxide with 1000 ml. (1 part) of a xylene solvent which consistsof a mixture of ortho and para xylene as well as some ethyl benzene.This premix is then added to the black liquor solution and stirred for 5minutes. While the mixture is being stirred 500 ml. (0.5 part) of 80%acetic acid is added slowly over 5 minutes. The viscosity of the mixturestarts to thicken and then thins out again. At this time another 100 ml.(0.1 part) of 80% acetic acid is added until the pH of the mixture is inthe preferred range of 7.8 to 8.2. The mixture is then stirred foranother 5 minutes, and then the agitation stopped. The mixture is thenallowed to stand and at the end of one-half hour a layer has formedwhich contains 1950 gms. of lignin.

EXAMPLE 17

This example illustrates the extraction or separation of lignin fromkraft black liquor (50% solids) with cyclohexanone, an organic ketone.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor into a5-gallon vessel provided with some means of agitation. Then add 1000 ml.(1 part) water and stir. To this mixture is then added 2000 ml. (2parts) of cyclohexanone and stirred for 5 minutes. Then 350 ml. (0.35part) of 80% acetic acid is added slowly over a 15-minute interval,until the mixture is acidic. The addition of acid is stopped if themixture starts to foam due to the evolution of gases. The mixture isstirred for 15 minutes and the agitation stopped. When the mixture isacidic, it normally will have a light brown color. The lignin layerwhich separates produces 805 gms. of lignin.

EXAMPLE 18

This example illustrates the separation or extraction of lignin fromkraft black liquor (50% solids) with isophorone, an organic ketone.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor into a5-gallon vessel provided with some means of agitation. Then add 1000 ml.(1 part) water and stir. To this mixture is then added 2000 ml. (2parts) of isophorone and stirred for 5 minutes. Then 350 ml. (0.35 part)of 80% acetic acid is added slowly over a 15-minute interval, until themixture is acidic. The addition of acid is stopped if the mixture startsto foam due to the evolution of gases. The mixture is stirred for 15minutes and the agitation stopped. When the mixture is acidic, itnormally will have a light brown color. The lignin layer which separatesproduces 910 gms. of lignin.

EXAMPLE 19

This example illustrates the extraction of lignin from kraft ligninblack liquor (50% solids) with valeraldehyde, an organic aldehyde.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor into a5-gallon vessel provided with some means of agitation. Then add 1000 ml.(1 part) water and stir. To this mixture is then added 2000 ml. (2parts) of valeraldehyde and stirred for 5 minutes. Then 350 ml. (0.35part) of 80% acetic acid is added slowly over a 15-minute interval,until the mixture is acidic. The addition of acid is stopped if themixture starts to foam due to the evolution of gases. The mixture isstirred for 15 minutes and the agitation stopped. When the mixture isacidic, it normally will have a light brown color. The lignin layerwhich separates produces 715 gms. of lignin.

EXAMPLE 20

This example illustrates the separation or extraction of lignin fromkraft black liquor with butyraldehyde, an organic aldehyde.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor into a5-gallon vessel provided with some means of agitation. Then add 1000 ml.(1 part) water and stir. To this mixture is then added 2000 ml. (2parts) of butyraldehyde and stirred for 5 minutes. Then 350 ml. (0.35part) of 80% acetic acid is added slowly over a 15-minute interval,until the mixture is acidic. The addition of acid is stopped if themixture starts to foam due to the evolution of gases. The mixture isstirred for 15 minutes and the agitation stopped. When the mixture isacidic, it normally will have a light brown color. The lignin layerwhich separates produces 435 gms. of lignin.

EXAMPLE 21

This example illustrates the separation or extraction of lignin fromkraft black liquor (50% solids) into butyl ether, an organic ether.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor into a5-gallon vessel provided with some means of agitation. Then add 1000 ml.(1 part) water and stir. To this mixture is then added 2000 ml. (2parts) of butyl ether and stirred for 5 minutes. Then 350 ml. (0.35part) of 80% acetic acid is added slowly over a 15-minute interval,until the mixture is acidic. The addition of acid is stopped if themixture starts to foam due to the evolution of gases. The mixture isstirred for 15 minutes and the agitation stopped. When the mixture isacidic, it normally will have a light brown color. The lignin layerwhich separates produces 565 gms. of lignin.

EXAMPLE 22

This example illustrates the separation or extraction of lignin fromkraft black liquor (50% solids) with hexyl acetate, an organic ester.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor into a5-gallon vessel provided with some means of agitation. Then add 1000 ml.(1 part) water and stir. To this mixture is then added 2000 ml. (2parts) of hexyl acetate and stirred for 5 minutes. Then 350 ml. (0.35part) of 80% acetic acid is added slowly over a 15-minute interval,until the mixture is acidic. The addition of acid is stopped if themixture starts to foam due to the evolution of gases. The mixture isstirred for 15 minutes and the agitation stopped. When the mixture isacidic, it normally will have a light brown color. The lignin layerwhich separates produces 407 gms. of lignin.

EXAMPLE 23

This example illustrates the separation or extraction of lignin fromkraft black liquor (50% solids) with heptyl acetate, an organic ester.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor into a5-gallon vessel provided with some means of agitation. Then add 1000 ml.(1 part) water and stir. To this mixture is then added 2000 ml. (2parts) of heptyl acetate and stirred for 5 minutes. Then 350 ml. (0.35part) of 80% acetic acid is added slowly over a 15-minute interval untilthe mixture is acidic. The addition of acid is stopped if the mixturestarts to foam due to the evolution of gases. The mixture is stirred for15 minutes and the agitation stopped. When the mixture is acidic, itnormally will have a light brown color. The lignin layer which separatesproduces 420 gms. of lignin.

EXAMPLE 24

This example illustrates the separation or extraction of lignin fromkraft black liquor (50% solids) with amyl acetate, an organic ester.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor into a5-gallon vessel provided with some means of agitation. Then add 1000 ml.(1 part) water and stir. To this mixture is then added 2000 ml. (2parts) of amyl acetate and stirred for 5 minutes. Then 350 ml. (0.35part) of 80% acetic acid is added slowly over a 15-minute interval,until the mixture is acidic. The addition of acid is stopped if themixture starts to foam due to the evolution of gases. The mixture isstirred for 15 minutes and the agitation stopped. When the mixture isacidic, it normally will have a light brown color. The lignin layerwhich separates produces 570 gms. of lignin.

EXAMPLE 25

This example illustrates the separation or extraction of lignin fromkraft black liquor (50% solids) into iso-amyl acetate, an organic ester.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor into a5-gallon vessel provided with some means of agitation. Then add 1000 ml.(1 part) water and stir. To this mixture is then added 2000 ml. (2parts) of iso-amyl acetate and stirred for 5 minutes. Then 350 ml. (0.35part) of 80% acetic acid is added slowly over a 15-minute interval,until the mixture is acidic. The addition of acid is stopped if themixture starts to foam due to the evolution of gases. The mixture isstirred for 15 minutes and the agitation stopped. When the mixture isacidic, it normally will have a light brown color. The lignin layerwhich separates produces 580 gms. of lignin.

EXAMPLE 26

This example illustrates the separation or extraction of lignin fromkraft black liquor (50% solids) into phenyl acetate, an organic ester.

PROCEDURE: Charge 4000 ml. (4 parts) of kraft black liquor into a5-gallon vessel provided with some means of agitation. Then add 1000 ml.(1 part) water and stir. To this mixture is then added 2000 ml. (2parts) of phenyl acetate and stirred for 5 minutes. Then 350 ml. (0.35part) of 80% acetic acid is added slowly over a 15-minute interval,until the mixture is acidic. The addition of acid is stopped if themixture starts to foam due to the evolution of gases. The mixture isstirred for 15 minutes and the agitation stopped. When the mixture isacidic, it normally will have a light brown color. The lignin layerwhich separates produces 850 gms. of lignin.

The lignin layer containing the solvent and lignin in the examples abovemay be utilized in exactly this form or the lignin may be separated fromthe solvent simply by drying or spray drying which simply evaporates thesolvent under atmospheric or vacuum conditions leaving the lignin insolid form. The following Example 26A illustrates this method of drying.

EXAMPLE 26A

This example illustrates the preparation of a spray-dried lignin powder,from kraft black liquor.

PROCEDURE: Charge 4000 gms. (4 parts) of the solvent-lignin layerseparated in Example 16 into a 5-gallon vessel. Then add 2000 gms. (2parts) of a volatile solvent such as acetone or methyl ethyl ketone andstir. This mixture is then spray-dried where the reduced pressureremoves the solvents and the powdered lignin remains.

This method of recovery of lignin from waste black liquor from the kraftprocess is highly advantageous over previous methods which involved theprecipitating of lignin from an aqueous solution, filtering the ligninand then drying the lignin. Lignin so precipitated is to some degree incolloidal form and in such form will pass through most filters and tothis extent is not recoverable. The present invention allows the ligninto be purified by the separation of the inorganic materials includingthe pulping chemicals into the water layer, as well as all water-solublematerial. This is very useful because a polymer may be made from thelignin without having the materials in the water layer interfere withthe properties of the polymer. Another advantage is that thelignin-solvent combination presents the lignin in a liquid phase whereit can be conveniently reacted with other chemicals to produce otheruseful end products such as resins, adhesives, paints and the like.

The uses of lignin so recovered are extensive. Lignins have foundextensive uses as fillers and extenders for various resins. It has beenused as a dispersant, emulsifier, grinding aid, protein precipitator,and sequestering agent depending on the particular nature of the lignin.

Lignin can be converted chemically to organic chemicals, for examplevanillin, methyl mercaptan and dimethyl sulfide. The potential uses oflignin are quite extensive.

The following examples illustrate the use of the lignin-solvent layerproduced in accordance with the teachings of Examples 1 through 26, tomake a useful end product of an epoxide-lignin resin by way of variouschemical intermediates. These examples relate to producing unsaturatedreactive end groups on the lignin molecule which end groups are readilyamenable to epoxidation to produce epoxide-lignin resins. These examplesinclude the placing of an unsaturated carbonyl group on the ligninmolecule such as an unsaturated ketone ester, aldehyde or acid. Theyalso include the placing of an unsaturated nitrogen containing compoundon the lignin molecule such as an unsaturated nitrile or amide.

EXAMPLE 27

This example illustrates the reaction of extracted or separated ligninwith mesityl oxide and formaldehyde, to produce a lignin unsaturatedcarbonyl intermediate.

PROCEDURE: Charge 1000 gms. (1 part) of the lignin-solvent layer fromExample 5 into a 5-liter, 3-neck, round-bottom flask equipped with athermometer, dropping funnel and mechanical stirrer. Add 200 ml. (0.2part) of 38% aqueous formaldehyde dropwise over a 10-minute interval,while stirring. Then add 200 ml. (0.2 part) of deionized water and stirfor 5 minutes and add 30 ml. (0.03 part) of triethylamine and stir for30 minutes. The dropping funnel is replaced with a water-cooledcondenser. The mixture is now heated to reflux and refluxed for 30minutes. The heat is removed and the mixture is stirred while cooling toroom temperature. All of the materials appear as seemingly a homogenousliquid. This reaction of the lignin, mesityl oxide and formaldehyde isbelieved to put unsaturated carbonyl groups onto the lignin molecule.These groups are reactive and may be epoxidized as is disclosed infurther examples.

EXAMPLE 28

This example illustrates the preparation of an unsaturated carbonylintermediate from extracted lignin, mesityl oxide and formaldehyde.

PROCEDURE: Charge 1600 gms. (1.6 parts) of the separated lignin-solventlayer from Example 5 into a 5-liter, 3-neck, round-bottom flask equippedwith a dropping funnel thermometer, and mechanical stirrer. Then add 100ml. (0.1 part) of 38% aqueous formaldehyde dropwise over 15 minuteswhile the extracted lignin is being stirred. Then add 300 ml. (0.3 part)of deionized water, over a 10-minute interval. The mixture is stirredwhile 30 ml. (0.03 part) of triethylamine is added dropwise over a10-minute interval. The mixture is then stirred for half an hour. Thedropping funnel is replaced with a water-cooled condenser. The mixtureis heated to reflux which requires a half hour. Then the mixture isrefluxed for 30 minutes and then cooled to room temperature over 30minutes. The lignin is believed to have an unsaturated carbonylstructure which is subsequently used for epoxidation.

EXAMPLE 29

This example illustrates the preparation of a reaction intermediateusing mesityl oxide and formaldehyde. In order to increase the number ofunsaturated carbonyl groups the amount of mesityl oxide and formaldehydeis increased accordingly.

PROCEDURE: Charge 1600 gms. (1.6 parts) of the separated lignin-mesityloxide from Example 5 into a 5-liter, 3-neck, round-bottom flask equippedwith a dropping funnel, thermometer and mechanical stirrer. Then add 200ml. (0.2 part) of mesityl oxide and stir for 15 minutes. Then add 300ml. (0.3 part) of 38% aqueous formaldehyde dropwise over a 15-minuteinterval while the mixture is being stirred. To the mixture is thenadded 200 ml. (0.2 part) of deionized water dropwise over a 10-minuteinterval. Then 40 ml. (0.04 part) of triethylamine is added dropwiseover a 10-minute interval. The dropping funnel is replaced by awater-cooled condenser and the mixture is agitated for one-half hour andheated to reflux. The mixture is refluxed for one hour and afterwardscooled to room temperature.

EXAMPLE 30

This example illustrates the preparation of a reactive intermediatewhich can be used to prepare a lignin-epoxy resin which has a relativelyhigh number of epoxy groups.

PROCEDURE: Charge 1600 gms. (1.6 parts) of extracted or separatedlignin-solvent from Example 5 into a 5-liter, 3-neck, round-bottom flaskequipped with a dropping funnel thermometer, and mechanical stirrer.Then add 400 ml. (0.4 part) of mesityl oxide and stir for 15 minutes.Then add 400 ml. (0.4 part) of 38% aqueous formaldehyde over a 30-minuteinterval. To the mixture is then added 200 ml. (0.2 part) of deionizedwater dropwise over a 10-minute interval. Then 50 ml. (0.05 part) oftriethylamine is added dropwise over a 10-minute interval. The droppingfunnel is replaced by a water-cooled condenser and the mixture stirredfor 30 minutes, and then heated to reflux. The mixture is refluxed forone hour and 30 minutes and afterwards, cooled to room temperature byremoving the heat and allowing the mixture to stir.

Examples 27, 28, 29 and 30 have illustrated the use of thelignin-solvent material from Example 5 in the reaction to produce theunsaturated carbonyl group on the lignin molecule. It will be understoodby those skilled in the art that the lignin-solvent separation from allof the Examples 1 through 26 can be used in essentially the same way.

EXAMPLE 31

This example illustrates the epoxidation of a reactive intermediateprepared from lignin, mesityl oxide and formaldehyde with hydrogenperoxide.

PROCEDURE: Charge 2000 gms. (2 parts) of Example 27 into a 5-liter,3-neck, round-bottom flask, equipped with a dropping funnel, thermometerand mechanical stirrer. Cool the mixture to 5° to 10° C. with an icebath or other cooling equipment. Premix 10 gms. (0.01 part) of magnesiumsulfate in 100 ml. (0.1 part) of deionized water. Add this to themixture dropwise over a 10-minute interval while the mixture is beingstirred. Premix 11 gms. of sodium hydroxide in 100 ml. (0.1 part) ofdeionized water. While the mixture is being maintained between 5° and10° C. with an ice bath, 30 ml. (0.03 part) of 30% hydrogen peroxide isadded dropwise over 30 minutes. The mixture is constantly being stirredduring this addition. If the temperature should rise above 10° C., theaddition of hydrogen peroxide is stopped until the temperature is lessthan 10° C. Once the addition of hydrogen peroxide is complete, 400 ml.(0.4 part) of deionized water is added and the mixture is stirred forone hour while the temperature is maintained between 5° and 10° C. Then100 gms. (0.1 part) of sodium sulfate is added and the mixture stirredfor 15 minutes. Afterwards, the mixture is poured into a separatoryfunnel. After two hours a layer of epoxy-lignin has started to form onthe top part of the separatory funnel and the undissolved sodium sulfatesettles on the bottom. This occurs as long as the lignin-epoxy has adensity less than that of the solution. The presence of low densitysolvents would enhance the separation if the lignin-epoxy has a densitygreater than the solution and settles to the bottom. After the formationof a layer is complete, the lignin-epoxy can be separated, and thenutilized as an epoxy-resin.

EXAMPLE 32

This example illustrates the preparation of a lignin-epoxy containingfour times the epoxy groups as in Example 31.

PROCEDURE: Charge 2000 gms. (2 parts) of Example 29 into a 5-liter,3-neck, round-bottom flask equipped with a dropping funnel, thermometerand mechanical stirrer. Cool the mixture from 5° to 10° C. with an icebath or other cooling equipment. Premix 10 gms. (0.01 part) of magnesiumsulfate into 100 ml. (0.1 part) of deionized water. Add this to themixture dropwise over a 10-minute interval while the mixture is beingstirred. Premix 11 gms. of sodium hydroxide in 100 ml. (0.1 part) ofdeionized water. While the mixture is being maintained between 5° and10° C. with an ice bath, 120 ml. (0.120 part) of 30% aqueous hydrogenperoxide is added dropwise over 30 minutes. The mixture is constantlybeing stirred during this addition. If the temperature should rise over10° C., the addition of hydrogen peroxide is stopped until thetemperature is less than 10° C. Once the addition of hydrogen peroxideis complete, 400 ml. (0.4 part) of deionized water is added and themixture is stirred for one hour while the temperature is maintainedbetween 5° to 10° C. Then 100 gms. (0.1 part) of sodium sulfate is addedand the mixture stirred for 15 minutes. Afterwards, the mixture ispoured into a separatory funnel. After two hours, a layer ofepoxy-lignin has started to form on the top part of the separatoryfunnel and the undissolved sodium sulfate settles on the bottom.

EXAMPLE 33

This example illustrates the preparation of a lignin-epoxy containingeight times the epoxy groups as in Example 31.

PROCEDURE: Charge 2000 gms. (2 parts) of Example 30 into a 5-liter,3-neck, round-bottom flask equipped with a dropping funnel, thermometer,and mechanical stirrer. Cool the mixture between 5° to 10° C. with anice bath or other cooling equipment. Premix 10 gms. (0.01 part) ofmagnesium sulfate into 100 ml. (0.1 part) of deionized water. Add thisto the mixture dropwise over a 10-minute interval while the mixture isbeing stirred. Premix 11 gms. of sodium hydroxide in 100 ml. (0.1 part)of deionized water. While the mixture is being maintained between 5° and10° C. with an ice bath, 240 ml. (0.240 part) of 30% aqueous hydrogenperoxide is added dropwise over one hour. The mixture is constantlybeing stirred during this addition. If the temperature should rise above10° C., the addition of hydrogen peroxide is stopped until thetemperature is less than 10° C. Once the addition of hydrogen peroxideis complete, 400 ml. (0.4 part) of deionized water is added and themixture is stirred for one hour while the temperature is beingmaintained between 5° to 10° C. Then 100 gms. (0.1 part) of sodiumsulfate is added and the mixture stirred for 15 minutes. Afterwards, themixture is poured into a separatory funnel. After two hours, a layer hasstarted to form on the top part of the separatory funnel and theundissolved sodium sulfate settles on the bottom.

EXAMPLE 34

This example illustrates the preparation of epoxide groups on the ligninmolecule by reacting lignin that contains unsaturated carbonyl groupswith sodium peroxide.

PROCEDURE: Charge 2000 gms. (2 parts) of Example 27 into a 5-liter,3-neck, round-bottom flask equipped with a dropping funnel, thermometerand mechanical stirrer. Cool the mixture to 5° to 10° C. with an icebath or other cooling equipment. Premix 10 gms. (0.01 part) of magnesiumsulfate into 100 ml. (0.1 part) of deionized water. Add this to themixture dropwise over a 10-minute interval while the mixture is beingstirred. Premix 11 gms. of sodium hydroxide in 100 ml. (0.1 part) ofdeionized water. While the mixture is being maintained between 5° and10° C. with an ice bath, 20 gms. (0.02 part) of sodium peroxide is addedgradually over 30 minutes. The mixture is constantly being stirredduring this addition. If the temperature should rise above 10° C., theaddition of sodium peroxide is stopped until the temperature is lessthan 10° C. Once the addition of sodium peroxide is complete, 400 ml.(0.4 part) of deionized water is added and the mixture is stirred forone hour while the temperature is being maintained between 5° to 10° C.Then 100 gms. (0.1 part) of sodium sulfate is added and the mixturestirred for 15 minutes. Afterwards, the mixture is poured into aseparatory funnel. After two hours, a layer has started to form on thetop part of the separatory funnel and the dissolved sodium sulfatesettles on the bottom. This occurs as long as the lignin-epoxy has adensity less than that of the solution. The presence of low-densitysolvents would enhance the separation if the lignin-epoxy has densitygreater than the solution and settles to the bottom. After the formationof a layer is complete, the lignin-epoxy can be separated, and thenutilized as an epoxy-resin.

EXAMPLE 35

This example illustrates the epoxidation of a reactive intermediateprepared from mesityl oxide, lignin and formaldehyde by sodium peroxide.

PROCEDURE: Charge 2000 gms. (2 parts) of Example 29 into 5-liter,3-neck, round-bottom flask equipped with a dropping funnel, thermometerand mechanical stirrer. Cool the mixture between 5° to 10° C. with anice bath or other cooling equipment. Premix 10 gms. (0.01 part) ofmagnesium sulfate into 100 ml. (0.1 part) of deionized water. Add thisto the mixture dropwise over a 10-minute interval while the mixture isbeing stirred. Premix 11 gms. of sodium hydroxide in 100 ml. (0.1 part)of deionized water. While the mixture is being maintained between 5° to10° C. with an ice bath, 20 gms. (0.02 part) of sodium peroxide is addedgradually over 30 minutes. The mixture is constantly being stirredduring this addition. If the temperature should rise above 10° C., theaddition of sodium peroxide is stopped until the temperature is lessthan 10° C. Once the addition of sodium peroxide is complete, 400 ml.(0.4 part) of deionized water is added and the mixture is stirred forone hour while the temperature is being maintained between 5° to 10° C.Then 100 gms. (0.1 part) of sodium sulfate is added and the mixturestirred for 15 minutes. Afterwards, the mixture is poured into aseparatory funnel. After two hours, a layer has started to form on thetop part of the separatory funnel and the undissolved sodium sulfatesettles on the bottom.

EXAMPLE 36

This example illustrates the preparation of a lignin-epoxy containingtwice the epoxy groups as Example 35.

PROCEDURE: Charge 2000 gms. (2 parts) of Example 29 into a 5-liter,3-neck, round-bottom flask equipped with a dropping funnel, thermometer,and mechanical stirrer. Cool the mixture between 5° to 10° C. with anice bath. Premix 10 gms. (0.01 part) of magnesium sulfate into 100 ml.(0.1 part) of deionized water. Add this to the mixture dropwise over a10-minute interval while the mixture is stirred. Premix 11 gms. (0.11part) of sodium hydroxide in 100 ml. (0.1 part) of deionized water.While the mixture is being maintained between 5° to 10° C. with an icebath, 40 gms. (0.04 part) of sodium peroxide is added gradually over a45-minute period. The mixture is constantly being stirred during thisaddition. If the temperature should rise above 10° C., the addition ofsodium peroxide is stopped until the temperature is less than 10° C.Once the addition of sodium peroxide is complete, 400 ml. (0.4 part) ofdeionized water is added and the mixture is stirred for one hour whilebeing maintained in the 5° to 10° C. range. Then 100 gms. (0.1 part) ofsodium sulfate is added and the mixture stirred for 15 minutes.Afterwards, the mixture is poured into a separatory funnel. After twohours, a layer has started to form on the top in the separatory funneland the undissolved sodium sulfate settles on the bottom.

EXAMPLE 37

This example illustrates the epoxidation of a reactive ligninintermediate with sodium peroxide, which contains four times the epoxygroups as Example 35.

PROCEDURE: Charge 2000 gms. (2 parts) of Example 30 into a 5-liter,3-neck, round-bottom flask equipped with a dropping funnel, thermometerand mechanical stirrer. Cool the mixture between 5° to 10° C. with anice bath. Premix 10 gms. (0.01 part) of magnesium sulfate into 100 ml.(0.1 part) of deionized water. Add this to the mixture dropwise over a10-minute interval while the mixture is stirring. Premix 11 gms. (0.11part) of sodium hydroxide in 100 ml. (0.1 part) of deionized water.While the mixture is being maintained between 5° to 10° C. with an icebath, 80 gms. (0.08 part) of sodium peroxide is added gradually over aone-hour period. The mixture is constantly being stirred during thisaddition. If the temperature should rise above 10° C., the addition ofsodium peroxide is stopped until the temperature is less than 10° C.Once the addition of sodium peroxide is complete, 400 ml. (0.4 part) ofdeionized water is added and the mixture is stirred for one hour whilebeing maintained in the 5° to 10° C. range. Then 100 gms. (0.1 part) ofsodium sulfate is added and the mixture stirred for 15 minutes.Afterwards, the mixture is poured into a separatory funnel. After twohours, a layer has started to form on the top in the separatory funneland the undissolved sodium sulfate settles on the bottom.

EXAMPLE 38

This example illustrates the reaction of acrylonitrile with lignin toproduce an unsaturated amide or intermediate which is chemiclly bondedto the lignin molecule. This unsaturated intermediate can then beepoxidized using the procedures of Examples 31 through 37.

PROCEDURE: Charge 1600 gms. (1.6 parts) of the separated lignin-butylether from Example 21 into a 5-liter, 3-neck, round-bottom flaskequipped with a dropping funnel, thermometer and mechanical stirrer.Then add 200 ml. (0.2 part) of acrylonitrile and stir for 15 minutes.Then add 300 ml. (0.3 part) of 38% aqueous formaldehyde dropwise over a15-minute interval while the mixture is being stirred. To the mixture isthen added 200 ml. (0.2 part) of deionized water dropwise over a10-minute interval. Then 40 ml. (0.04 part) of triethylamine is addeddropwise over a 10-minute interval. The dropping funnel is replaced by awater-cooled condenser and the mixture is agitated for one-half hour andheated to reflux. The mixture is refluxed for one hour and afterwards,cooled to room temperature.

EXAMPLE 39

This example illustrates the reaction of acrolein with lignin to producean unsaturated carbonyl which is chemically bonded to the ligninmolecule. This can be epoxidized by the procedure of Examples 31 through37.

PROCEDURE: Charge 1600 gms. (1.6 parts) of the separated lignin-mesityloxide from Example 21 into a 5-liter, 3-neck, round-bottom flaskequipped with a dropping funnel, thermometer, and mechanical stirrer.Then add 200 ml. (0.2 part) of acrolein and stir for 15 minutes. Thenadd 300 ml. (0.3 part) of 38% aqueous formaldehyde dropwise over a15-minute interval while the mixture is being stirred. To the mixture isthen added 200 ml. (0.2 part) of deionized water dropwise over a10-minute interval. Then 40 ml. (0.04 part) of triethylamine is addeddropwise over a 10-minute interval. The dropping funnel is replaced by awater-cooled condenser and the mixture is agitated for one-half hour andheated to reflux. The mixture is refluxed for one hour and afterwards,cooled to room temperature.

EXAMPLE 40

This example illustrates the reaction of extracted or separated ligninwith cyanoacetic acid to produce an unsaturated nitrile which ischemically bonded to the lignin molecule.

PROCEDURE: Charge 2000 gms. (2 parts) of extracted or separated ligninfrom Example 16 into a 5-liter, 3-neck, round-bottom flash equipped witha mechanical stirrer, thermometer and dropping funnel. Then premix 40gms. (0.04 part) of sodium hydroxide in 300 ml. of deionized water andadd dropwise over 15 minutes. The mixture is then stirred for 15minutes. Then premix 100 gms. (0.1 part) of cyanoacetic acid in 200 gms.(0.2 part) of deionized water. Add this mixture dropwise over a periodof one-half hour. Then stir this mixture at room temperature for onehour. Then heat to reflux and reflux for one hour. Afterwards, themixture is cooled to room temperature.

EXAMPLE 41

This example illustrates the reaction of extracted or separated ligninwith ethyl cyanoacetate t produce an unsaturated nitrile which ischemically bonded to the lignin molecule.

PROCEDURE: Charge 2000 gms. (2 parts) of extracted or separated ligninfrom Example 16 into a 5-liter, 3-neck, round-bottom flash equipped witha mechanical stirrer, thermometer and dropping funnel. Then premix 40gms. (0.04 part) of sodium hydroxide in 300 ml. of deionized water andadd dropwise over 15 minutes. The mixture is then stirred for 15minutes. Then premix 100 gms. (0.1 part) of ethyl cyanoacetate in 200gms. (0.2 part) of deionized water. Add this mixture dropwise over aperiod of one-half hour. Then stir this mixture at room temperature forone hour. Then heat to reflux and reflux for one hour. Afterwards, themixture is cooled to room temperature.

EXAMPLE 42

This example illustrates the reaction of extracted or separated ligninwith methyl cyanoacetate to produce an unsaturated nitrile which ischemically bonded to the lignin molecule.

PROCEDURE: Charge 2000 gms. (2 parts) of extracted or separated ligninfrom Example 16 into a 5-liter, 3-neck, round-bottom flask equipped witha mechanical stirrer, thermometer and dropping funnel. Then premix 40gms. (0.04 part) of sodium hydroxide in 300 ml. of deionized water andadd dropwise over 15 minutes. Then premix 100 gms. (0.1 part) of methylcyanoacetate in 200 gms. (0.2 part) of deionized water. Add this mixturedropwise over a period of one-half hour. Then stir this mixture at roomtemperature for one hour. Then heat to reflux and reflux for one hour.Afterwards, the mixture is cooled to room temperature.

EXAMPLE 43

This example illustrates the reaction of lignin with diethyl malonate toproduce an unsaturated ester which can then be epoxidized.

PROCEDURE: Charge 2000 gms. (2 parts) of extracted or separated ligninfrom Example 16 into a 5-liter, 3-neck, round-bottom flask equipped witha mechanical stirrer, thermometer and dropping funnel. Then premix 40gms. (0.04 part) of sodium hydroxide in 300 ml. of deionized water andadd dropwise over 15 minutes. Then premix 100 gms. (0.1 part) of diethylmalonate in 200 gms. (0.2 part) of deionized water. Add this mixturedropwise over a period of one-half hour. Then stir this mixture at roomtemperature for one hour. Then heat to reflux and reflux for one hour.Afterwards, the mixture is cooled to room temperature.

EXAMPLE 44

This example illustrates the reaction of dimethyl malonate withextracted or separated lignin to produce an unsaturated ester which canthen be epoxidized with alkaline hydrogen peroxide.

PROCEDURE: Charge 2000 gms. (2 parts) of extracted or separated ligninfrom Example 16 into a 5-liter, 3-neck, round-bottom flask equipped witha mechanial stirrer, thermometer, and dropping funnel. Then premix 40gms. (0.04 part) of sodium hydroxide in 300 ml. of deionized water andadd dropwise over 15 minutes. Then premix 100 gms. (0.1 part) ofdimethyl malonate in 200 gms. (0.2 part) of deionized water. Add thismixture dropwise over a period of one-half hour. Then stir this mixtureat room temperature for one hour. Then heat to reflux and reflux for onehour. Afterwards, the mixture is cooled to room temperature.

EXAMPLE 45

This example illustrates the reaction of extracted or separated ligninwith malonic acid to produce an unsaturated acid which can then beepoxidized.

PROCEDURE: Charge 2000 gms. (2 parts) of extracted or separated ligninfrom Example 16 into a 5-liter, 3 -neck, round-bottom flask equippedwith a mechanical stirrer, thermometer, and dropping funnel. Then premix40 gms. (0.04 part) of sodium hydroxide in 300 ml. of deionized waterand add dropwise over 15 minutes. Then premix 100 gms. (0.1 part) ofmalonic acid in 200 gms. (0.02 part) of deionized water. Add thismixture dropwise over a period of one-half hour. Then stir this mixtureat room temperature for one hour. Then heat to reflux and reflux for onehour. Afterwards, the mixture is cooled to room temperature.

Epoxidation of Examples 40 through 45 can be carried out in the samemanner as disclosed in Examples 31 through 37.

The following examples teach the use of and method of making several endproducts from the epoxide-lignin resins of Examples 31 through 37.

EXAMPLE 46

This example illustrates the preparation of an adhesive from epoxidizedlignin.

A. 100 parts epoxidized lignin (from Examples 33)

50 parts tabular alumina

B. 50 parts Thiokol LP-30, (polysulfide resin) 10 parts DMP-30tri-(dimethylaminoethyl) Phenol (catalyst)

PROCEDURE: The filler (tabular alumina) is mixed with the epoxidizedlignin preferably by grinding on a 3-roll paint mill. Then the mixtureof liquid polysulfide and catalyst is blended in, care being taken toavoid the entrapment of air. Both A and B are stable but their mixturehas a short pot life, well under an hour, therefore, mix only enough for10 to 15 minutes of operation. Because of DMP-30, cure can take place atroom temperature.

EXAMPLE 47

This example illustrates the preparation of an adhesive from epoxidizedlignin, with a polyamide resin such as Versamid 115 resin.

A. 100 parts of epoxidized lignin from Example 33.

B. 70 parts Versamid 115 resin.

C. Filler as desired.

PROCEDURE: Simply blend all of the components together. The Versamidscure slowly at room temperature which allows for longer working times.

EXAMPLE 48

This example illustrates the preparation of an adhesive from epoxidizedlignin, Versamid polyamide, and a curing agent to provide a faster cure.

A. 100 parts of epoxidized lignin from Example 33.

B. 35 parts Versamid 115

C. 5 parts DMP-30 tri-(dimethylaminoethyl) phenol (catalyst)

D. Filler as desired

PROCEDURE: The filler is blended with the epoxidized lignin and areactive diluent is added to reduce the viscosity if necessary.

EXAMPLE 49

This example illustrates the preparation of a plastic from epoxidizedlignin.

PROCEDURE:

A. 100 parts of epoxidized lignin from Example 31.

B. 30 parts Lubrizol CA-23 epoxy curing agent (polyamide)

A and B are blended together and heated slowly until the mixture thinsout. Then the mixture is heated under agitation for one-half hour untildroplets of the mixture form long fibers of approximately 2 ft. inlength. At this time the mixture can then be cast into a mold. Oncooling, a dark solid plastic results

EXAMPLE 50

This example illustrates the preparation of a plastic from epoxidizedlignin by using an aliphatic amine curing agent.

A. 100 parts of epoxidized lignin from Example 32.

B. 15 parts triethylenetetramine

C. 100 parts of epoxidized lignin from Example 32.

PROCEDURE: Blend A and B and heat to 100° C. for one-half hour and thenadd C. The mixture is then heated at 200° C. until fibers 2 ft. longform from the droplets of the mixture. The mixture is then cast into amold and a tough, dark plastic results.

EXAMPLE 51

This example illustrates the preparation of a plastic from epoxidizedlignin and a polysulfide resin.

A. 100 parts of epoxidized lignin from Example 33.

B. 120 parts of Thiokol polysulfide resin (LP-3)

C. 10 parts of tri-(dimethyaminoethyl) phenol

PROCEDURE: Blend B and C and then add A and mix well for 10 minutes. Themixture is then poured into a mold and at the end of 6 hours, has curedto a tough plastic.

Another illustration of the invention involves the use of a lignin whichhas been separated from the waste black cooking liquor of the kraftpulping process in a manner different than that disclosed above.

This lignin is separated, in principle, by reducing the pH of the blackliquor to a level where a lignin fraction precipitates or separates fromthe aqueous medium. This lignin is normally separated and driedresulting in a powder-like product. The lignin resulting may, also, beproduced in a slurry-like suspension. The pH of the black liquor isnormally reduced by the addition of an acid and separation of lignin mayresult at a pH 8 or 9 and, also, results at a pH below 7. Thisillustration of the invention is best understood from the followingexamples all of which involve the use of a lignin produced as justdescribed above.

EXAMPLE 52

This example illustrates the reaction of lignin, produced as justdescribed above, with mesityl oxide and formaldehyde to produce a ligninunsaturated carbonyl intermediate.

PROCEDURE: Dissolve 18 gms. (0.018 part) of sodium hydroxide into 1600gms. (1.6 parts) of deionized water. Then slowly add 500 gms. (0.5 part)of Indulin AT (a powdered kraft lignin produced by Westvaco Corporation)while the mixture is agitated. Then charge this premix into a 5-liter,3-neck, round-bottom flask equipped with a thermometer, dropping funnel,and mechanical stirrer. Add 98 gms. (0.098 part) of mesityl oxidedropwise over ten minutes while the mixture is agitated. Then add 80gms. (0.08 part) of 40% aqueous formaldehyde dropwise over a ten-minuteinterval. To this mixture add 8 gms. (0.008 part) of triethylamine.

The dropping funnel is replaced with a water cooled condenser. Themixture is heated to reflux and refluxed for 30 minutes. The heat isremoved and the mixture is stirred while cooling to room temperature.All of the materials appear as a seemingly homogenous liquid. Thisreaction of the lignin, mesityl oxide and formaldehyde is believed toput unsaturated carbonyl groups onto the lignin molecule. These groupsare reactive and may be epoxidized as is disclosed in further examples.

EXAMPLE 53

This example illustrates the reaction of a lignin with mesityl oxide andformaldehyde to produce a lignin unsaturated carbonyl intermediate. Thisexample will produce a lignin-epoxy resin with fewer epoxide groups thanExample 52.

PROCEDURE: Dissolve 18 gms. (0.018 part) of sodium hydroxide into 1600gms. (1.6 parts) of deionized water. Then slowly add 500 gms. (0.5 part)of Indulin AT (a powdered kraft lignin produced by Westvaco Corporation)while the mixture is being agitated. Then charge this premix into a5-liter, 3-neck, round-bottom flask equipped with a thermometer,dropping funnel, and mechanical stirrer. Add 18 gms. (0.018 part) ofmesityl oxide dropwise over ten minutes, while the mixture is agitated.Then add 14 gms. (0.014 part) of 40% aqueous formaldehyde dropwise overa ten-minute interval. To this mixture add 8 gms. (0.008 part) oftriethylamine.

The dropping funnel is replaced with a water-cooled condenser. Themixture is heated to reflux and refluxed for 30 minutes. The heat isremoved and the mixture is stirred while cooling to room temperature.All of the materials appear as a seemingly homogenous liquid. Thisreaction of the lignin, mesityl oxide and formaldehyde is believed toput unsaturated carbonyl groups onto the lignin molecule. These groupsare reactive and may be epoxidized as is disclosed in further examples.

EXAMPLE 54

This example illustrates the epoxidation of a reactive intermediateprepared from lignin, such as Indulin At, mesityl oxide and formaldehydewith hydrogen peroxide.

PROCEDURE: Charge 2300 gms. (2.3 parts) of Example 52 into a 5-liter,3-neck round bottom flask equipped with a dropping funnel, thermometerand mechanical stirrer. Cool the mixture to 5° to 10° C. with an icebath or other cooling equipment.

Premix 8 gms. (0.008 parts) of magnesium sulfate in 200 gms. (0.2 parts)of deionized water. Add this mixture dropwise over a ten-minute intervalwhile the mixture is being stirred. While the mixture is beingmaintained between 5° and 10° C. with an ice bath, 100 ml. (0.1 part) of30% hydrogen peroxide is added dropwise over 30 minutes. The mixture isconstantly being stirred during this addition. If the temperature shouldrise above 10° C., the addition of hydrogen peroxide is stopped untilthe temperature is less than 10° C. Once the addition of hydrogenperoxide is complete the mixture is stirred for one hour while thetemperature is being maintained between 5° and 10° C. Then the mixtureis poured into a 3000 ml. beaker or like container. Then 100 gms. (0.1part) of sodium sulfate is added and the mixture stirred for 15 minutes.The mixture now becomes very thick and the lignin-epoxy resin can now beeasily separated by various means, such as filtering or spray drying.The resin can also be separated from the reaction medium by acidifyingwith acetic, sulfuric or hydrochloric acid or with carbon dioxide gas,which causes the lignin-epoxy resin to become insoluble therebyprecipitating out of the reaction medium.

EXAMPLE 55

This example illustrates the epoxidation of a reactive intermediateprepared from lignin, such as Indulin AT, mesityl oxide andformaldehyde. This example also illustrates the separation of the finallignin-epoxy resin from the reaction mixture by the use of an acid suchas acetic acid.

PROCEDURE: Charge 2300 gms. (2.3 parts) of Example 52 into a 5-liter,3-neck round-bottom flask equipped with a dropping funnel, thermometerand mechanical stirrer. Cool the mixture to 5° to 10° C. with an icebath or other cooling equipment.

Premix 8 gms. (0.008 parts) of magnesium sulfate. in 200 gms. (0.2parts) of deionized water. Add this mixture dropwise over a ten-minuteinterval while the mixture is being stirred. While the mixture is beingmaintained between 5° and 10° C. with an ice bath, 100 ml. (0.1 part) of30% hydrogen peroxide is added dropwise over 30 minutes. The mixture isconstantly being stirred during this addition. If the temperature shouldrise above 10° C., the addition of hydrogen peroxide is stopped untilthe temperature is less than 10° C. Once the addition of hydrogenperoxide is complete the mixture is stirred for one hour while thetemperature is being maintained between 5° and 10° C. Premix 30 ml.(0.03 part) of glacial acetic acid in 70 ml. (0.07 part) of deionizedwater. This premix is then added slowly to the reaction mixture while itis being agitated. The mixture becomes very thick and the epoxy-ligninresin is no longer water-soluble and can be easily separated from thereaction solvents by various means such as filtering or spray-drying.

EXAMPLE 56

This example illustrates the epoxidation of a reactive intermediateprepared from lignin, such as Indulin AT, mesityl oxide and formaldehydeat 25° C. instead of 5° to 10° C.

PROCEDURE: Charge 2300 gms. (2.3 parts) of Example 52 into a 5-liter,3-neck, round-bottom flask equipped with a dropping funnel, thermometerand mechanical stirrer. Cool the mixture to 25° C. with an ice bath orother cooling equipment. Premix 8 gms. (0.008 part) of magnesium sulfatein 200 gms. (0.2 part) of deionized water. Add this mixture dropwiseover a ten-minute interval while the mixture is being stirred. While themixture is being maintained between 20° and 25° C. with an ice bath, 100ml. (0.1 part) of 30% hydrogen peroxide is added dropwise over 30minutes. The mixture is constantly being stirred during this addition.If the temperature should rise above 25° C., the addition of hydrogenperoxide is stopped until the temperature is less than 25° C. Once theaddition of hydrogen peroxide is complete the mixture is stirred for onehour while the temperature is maintained between 20° and 25° C. Then themixture is poured into a 3000 ml. beaker or like container. Then 100gms. (0.1 part) of sodium sulfate is added and the mixture stirred for15 minutes. The mixture now becomes very thick and the lignin-epoxyresin can now be easily separated by various means, such as filtering orspray drying.

EXAMPLE 57

This example illustrates the epoxidation of a reactive intermediateprepared from lignin, such as Indulin AT, mesityl oxide andformaldehyde. This epoxidation produces a lignin-epoxy resin with aboutone-fifth as many epoxy groups as Example 54.

PROCEDURE: Charge 2150 gms. (2.15 parts) of Example 53 into a 5-liter,3-neck, round-bottom flask equipped with a dropping funnel, thermometerand mechanical stirrer. Cool the mixture to 5° to 10° C. with an icebath or other cooling equipment. Premix 3 gms. (0.003 part) of magnesiumsulfate in 200 gms. (0.2 part) of deionized water. Add this mixturedropwise over a ten-minute interval while the mixture is being stirred.While the mixture is being maintained between 5° and 10° C., with an icebath, 17 ml. (0.017 part) of 30% hydrogen peroxide is added dropwiseover 30 minutes. The mixture is constantly being stirred during thisaddition. If the temperature should rise above 10° C., the addition ofhydrogen peroxide is stopped until the temperature is less than 10° C.Once the addition of hydrogen peroxide is complete the mixture isstirred for one hour while the temperature is being maintained between5° and 10° C. Then the mixture is poured into a 3000 ml. beaker or likecontainer. Then 100 gms. (0.1 part) of sodium sulfate is added and themixture stirred for 15 minutes. The mixture now becomes very thick andthe lignin-epoxy resin can now be easily separated by various means,such as filtering or spray drying.

EXAMPLE 58

This example illustrates the reaction of acrylonitrile with Indulin ATlignin to produce an unsaturated amide or intermediate which ischemically bonded to the lignin molecule. This unsaturated intermediatecan then be epoxidized by using the procedures of Examples 54 through57.

PROCEDURE: Dissolve 18 gms. (0.018 part) of sodium hydroxide into 1600gms. (1.6 parts) of deionized water. Then slowly add 500 gms. (0.5 part)of Indulin AT (a kraft lignin produced by Westvaco Corporation) whilethe mixture is being agitated. Then charge this premix into a 5-liter,3-neck round-bottom flask equipped with a thermometer, dropping funnel,and mechanical stirrer. Add 100 gms. (0.10 part) of acrylonitriledropwise over ten minutes while the mixture is being agitated. Then add80 gms. (0.08 part) of 40% aqueous formaldehyde dropwise over aten-minute interval. To this mixture add 8 gms. (0.008 part) oftriethylamine.

The dropping funnel is replaced with a water-cooled condenser. Themixture is heated to reflux and refluxed for 30 minutes. The heat isremoved and the mixture is stirred while cooling to room temperature.All of the materials appear as a seemingly homogenous liquid. Thisreaction of the lignin, acrylonitrile and formaldehyde is believed toput unsaturated amide groups onto the lignin molecule. These groups arereactive and may be epoxidized as is disclosed in further examples.

EXAMPLE 59

This example illustrates the reaction of acrolein with Indulin AT ligninto produce an unsaturated carbonyl which is chemically bonded to thelignin molecule. This unsaturated intermediate can then be epoxidized byusing the procedures of Examples 54 through 57.

PROCEDURE: Dissolve 18 gms. (0.018 part) of sodium hydroxide into 1600gms. (1.6 parts) of deionized water. Then slowly add 500 gms. (0.5 part)of Indulin AT (a kraft lignin produced by Westvaco Corporation) whilethe mixture is being agitated. Then charge this premix into a 5-liter,3-neck round-bottom flask equipped with a thermometer, dropping funnel,and mechanical stirrer. Add 60 gms. (0.060 part) of acrolein dropwiseover ten minutes while the mixture is being agitated. Then add 80 gms.(0.08 part) of 40% aqueous formaldehyde dropwise over a ten-minuteinterval. To this mixture add 8 gms. (0.008 part) of triethylamine.

The dropping funnel is replaced with a water-cooled condenser. Themixture is heated to reflux and refluxed for 30 minutes. The heat isremoved and the mixture is stirred while cooling to room temperature.All of the materials appear as a seemingly homogenous liquid. Thisreaction of the lignin, acrolein and formaldehyde is believed to putunsaturated carbonyl groups onto the lignin molecule. These groups arereactive and may be epoxidized as is disclosed in further examples.

EXAMPLE 60

This example illustrates the reaction of Indulin AT lignin withcyanoacetic acid to produce an unsaturated nitrile which is chemicallybonded to the lignin molecule. This unsaturated nitrile can then beepoxidized by using the procedures of Examples 54 through 57.

PROCEDURE: Dissolve 28 gms. (0.028 part) of sodium hydroxide into 1600gms. (1.6 parts) of deionized water. Then slowly add 500 gms. (0.5 part)of Indulin AT (a kraft lignin produced by Westvaco Corporation) whilethe mixture is agitated. Then charge this premix into a 5-liter, 3-neck,round-bottom flask equipped with a mechanical stirrer, thermometer, anddropping funnel. Then premix 100 gms. (0.10 part) of cyanoacetic acid in200 gms. (0.2 part) of deionized water. Add this mixture dropwise over aperiod of one-half hour. Then stir this mixture at room temperature forone hour. Then replace the dropping funnel with a water-cooledcondenser, heat to reflux and reflux for one hour. Afterward thereaction is cooled to room temperature.

EXAMPLE 61

This example illustrates the reaction of Indulin AT lignin with ethylcyanoacetate to produce an unsaturated nitrile which is chemicallybonded to the lignin molecule. This unsaturated nitrile can then beepoxidized by using the procedures of Examples 54 through 57.

PROCEDURE: Dissolve 28 gms. (0.028 part) of sodium hydroxide into 1600gms. (1.6 parts) of deionized water. Then slowly add 500 gms. (0.5 part)of Indulin AT (a kraft lignin produced by Westvaco Corporation) whilethe mixture is being agitated. Then charge this premix into a 5-liter,3-neck round-bottom flask equipped with a mechanical stirrer,thermometer, and dropping funnel. Then premix 120 gms. (0.12 part) ofethyl cyanoacetate in 200 gms. (0.2 part) of deionized water. Add thismixture dropwise over a period of one-half hour. Then stir this mixtureat room temperature for one hour. Then replace the dropping funnel witha water-cooled condenser, heat to reflux and reflux for one hour.Afterward the reaction is cooled to room temperature.

EXAMPLE 62

This example illustrates the reaction of Indulin AT lignin with methylcyanoacetate to produce an unsaturated nitrile which is chemicallybonded to the lignin molecule. This unsaturated nitrile can then beepoxidized by using procedures of Examples 54 through 57.

PROCEDURE: Dissolve 28 gms. (0.028 part) of sodium hydroxide into 1600gms. (1.6 parts) of deionized water. Then slowly add 500 gms. (0.5 part)of Indulin AT (a kraft lignin produced by Westvaco Corporation) whilethe mixture is being agitated. Then charge this premix into a 5-liter,3-neck round-bottom flask equipped with a mechanical stirrer,thermometer and dropping funnel. Then premix 110 gms. (0.11 part) ofmethyl cyanoacetate in 200 gms. (0.2 part) of deionized water. Add thismixture dropwise over a period of deionized water. Add this mixturedropwise over a period of one-half hour. Then stir this mixture at roomtemperature for one hour. Then replace the dropping funnel with awater-cooled condenser, heat to reflux and reflux for one hour.Afterwards the reaction is cooled to room temperature.

EXAMPLE 63

This example illustrates the reaction of Indulin AT lignin withdimethylmalonate to produce an unsaturated ester which is chemicallybonded to the lignin molecule. This unsaturated ester can then beepoxidized by using the procedures of Examples 54 through 57.

PROCEDURE: Dissolve 20 gms. (0.02 part) of sodium hydroxide into 1600gms. (1.6 parts) of deionized water. Then slowly add 500 gms. (0.5 part)of Indulin AT (a kraft lignin produced by Westvaco Corporation) whilethe mixture is agitated. Then charge this premix into a 5-liter, 3-neck,round-bottom flask equipped with a mechanical stirrer, thermometer, anddropping funnel. Then premix 140 gms. (0.14 part) of dimethylmalonate in200 gms. (0.2 part) of deionized water. Add this mixture dropwise over aperiod of one-half hour. Then stir this mixture at room temperature forone hour. Then replace the dropping funnel with a water-cooledcondenser, heat to reflux and reflux for one hour. Afterward thereaction is cooled to room temperature.

EXAMPLE 64

This example illustrates the reaction of Indulin AT lignin with malonicacid to produce an unsaturated acid which is chemically bonded to thelignin molecule. This unsaturated acid can then be epoxidized by usingprocedures of Examples 54 through 57.

PROCEDURE: Dissolve 28 gms. (0.028 part) of sodium hydroxide into 1600gms. (1.6 parts) of deionized water. Then slowly add 500 gms. (0.5 part)of Indulin AT (a kraft lignin produced by Westvaco Corporation) whilethe mixture is being agitated. Then charge this premix into a 5-liter,3-neck, round-bottom flask equipped with a mechanical stirrer,thermometer and dropping funnel. Then premix 110 gms. (0.11 part) ofmalonic acid in 200 gms. (0.2 part) of deionized water. Add this mixturedropwise over a period of one-half hour. Then stir this mixture at roomtemperature for one hour. Then replace the dropping funnel with awater-cooled condenser, heat to reflux and reflux for one hour.Afterward the reaction is cooled to room temperature.

EXAMPLE 65

This example illustrates the reaction of a lignin epoxy resin with apolyazelaic polyanhydride curing agent. This reaction produces a hard,glossy plastic whose properties depend on the ratio of curing agent tolignin-epoxy resin and also how long the material is cured.

PROCEDURE: Melt B in a suitable pyrex beaker and then add A and mix welland heat to 400° F. The mixture reacts to produce a viscous liquid whichon continued heating, will produce fibers of any length desired from abead drawn from the melt.

A=100 parts of dried epoxidized lignin from Example 54.

B=35 parts polyazelaic polyanhydride (purchased from Emery Industries).

EXAMPLE 66

This example illustrates the epoxidation of an Indulin AT unsaturatedcarbonyl with sodium peroxide.

PROCEDURE: Charge 2300 gms. (2.3 parts) of Example 52 into a 5-liter,3-neck, round-bottom flask equipped with a dropping funnel, thermometerand mechanical stirrer. Cool the mixture to 5° to 10° C. with an icebath or other cooling equipment.

Premix 8 gms. (0.008 part) of magnesium sulfate in 200 gms. (0.2 part)of deionized water. Add this mixture dropwise over a ten-minute intervalwhile the mixture is being stirred. While the mixture is beingmaintained between 5° and 10° C. with an ice bath, 80 gms. (0.08 part)of sodium peroxide dissolved in 200 ml. (0.2 part) of deionized water isadded dropwise over 30 minutes. The mixture is constantly being stirredduring this addition. If the temperature should rise above 10° C., theaddition of sodium peroxide is stopped until the temperature is lessthan 10° C. Once the addition of sodium peroxide is complete the mixtureis stirred for one hour while the temperature is being maintainedbetween 5° and 10° C. Then the mixture is poured into a 3000 ml. beakeror like container. Then 100 gms. (0.1 part) of sodium sulfate is addedand the mixture stirred for 15 minutes. The mixture now becomes verythick and the lignin-epoxy resin can now be easily separated by variousmeans, such as filtering or spray drying.

EXAMPLE 67

This example illustrates the epoxidation of an Indulin AT unsaturatedcarbonyl with sodium peroxide to produce an epoxy-lignin resin which hasone-fifth as many epoxy groups as Example 66.

PROCEDURE: Charge 2150 gms. (2.15 parts) of Example 53 into a 5-liter,3-neck, round-bottom flask equipped with a dropping funnel, thermometerand mechanical stirrer. Cool the mixture to 5° C. to 10° C. with an icebath or other cooling equipment.

Premix 3 gms. (0.003 part) of magnesium sulfate in 200 gms. (0.2 part)of deionized water. Add this mixture dropwise over a ten-minute intervalwhile the mixture is being stirred. While the mixture is beingmaintained between 5° and 10° C. with an ice bath, 16 gms. (0.016 part)of sodium peroxide dissolved in 200 ml. (0.20 part) of deionized wateris added dropwise over 30 minutes. The mixture is constantly stirredduring this addition. If the temperature should rise about 10° C., theaddition of sodium peroxide is stopped until the temperature is lessthan 10° C. Once the addition of sodium peroxide is complete the mixtureis stirred for one hour while the temperature is being maintainedbetween 5° and 10° C. Then the mixture is poured into a 3000 ml. beakeror line container. Then 100 gms. (0.1 part) of sodium sulfate is addedand the mixture stirred for 15 minutes. The mixture now becomes verythick and the lignin-epoxy resin can now be easily separated by variousmeans, such as filtering or spray drying.

EXAMPLE 68

This example illustrates the separation of lignin from kraft blackliquor by using decyl alcohol, an organic alcohol, which is a materialwhich is considered only a partial solvent for lignin.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100 ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of decyl alcohol. While this mixture is beingstirred, add 25 ml. (0.25 parts) of 80% acetic acid slowly over a fiveminute interval. As soon as the viscosity of the mixture starts toincrease the stirring may be discontinued and a layer starts to formwhich contains the lignin.

EXAMPLE 69

This example illustrates the separation of lignin from kraft blackliquor by using iso-octyl alcohol, an aliphatic alcohol, a partialsolvent for lignin.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100 ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of iso-octyl alcohol. While this mixture is beingstirred, add 26 ml. (0.25 parts) of 80% acetic acid slowly over a fiveminute interval. As soon as the viscosity of the mixture starts toincrease the stirring may be discontinued and a a layer starts to formwhich contains the lignin.

EXAMPLE 70

This example illustrates the separation of lignin from kraft blackliquor by using methyl amyl ketone, an organic ketone, a partial solventfor lignin.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100. ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of methyl amyl ketone. While this mixture is beingstirred, add 25 ml. (0.25 parts) of 80% acetic acid slowly over a fiveminute interval. As soon as the viscosity of the mixture starts toincrease the stirring may be discontinued and a layer starts to form.

EXAMPLE 71

This example illustrates the separation of lignin from kraft blackliquor by using Pluracol TP-740, a product of BASF WYANDOTTE, a liquidpolyoxypropylene derivative of trimethylolpropane. This material isnormally considered to be only a partial solvent for lignin. Thisexample also illustrates a very large market for lignin by combininglignin with various polyether polyols to produce various polyurethaneproducts.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100 ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of Pluracol TP-740. While this mixture is beingstirred, add 25 ml. (0.25 parts) of 80% acetic acid slowly over a fiveminute interval. As soon as the viscosity of the mixture starts toincrease the stirring may be discontinued and a layer starts to formwhich contains the lignin.

EXAMPLE 72

This example illustrates the separation of lignin from kraft blackliquor by using dicyclopentadiene alcohol. This material is normallyconsidered to be only a partial solvent for lignin.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100 ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of dicyclopentadiene alcohol. While this mixture isbeing stirred, add 25 ml. (0.25 parts) of 80% acetic acid slowly over afive minute interval. As soon as the viscosity of the mixture starts toincrease the stirring may be discontinued and a layer starts to formwhich contains the lignin.

EXAMPLE 73

This example illustrates the separation of lignin from kraft blackliquor by using 2-heptanone, an organic ketone. This material isnormally considered to be only a partial solvent for lignin.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100 ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of 2-heptanone. While this mixture is beingstirred, add 25 ml. (0.25 parts) of 80% acetic acid slowly over a fiveminute interval. As soon as the viscosity of the mixture starts toincrease the stirring may be discontinued and a layer starts to formwhich contains the lignin.

EXAMPLE 74

This example illustrates the separation of lignin from kraft liquor byusing dimethyl-4-heptanone, an organic ketone. This material is normallyconsidered to be only a partial solvent for lignin.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100 ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of dimethyl-4-heptanone. While this mixture isbeing stirred, add 25 ml. (0.25 parts) of 80% acetic acid slowly over afive minute interval. As soon as the viscosity of the mixture starts toincrease the stirring may be discontinued and a layer starts to formwhich contains the lignin.

EXAMPLE 75

This example illustrates the separation of lignin from kraft blackliquor by using xylene solvent which consists of a mixture of ortho andpara xylene as well as some ethyl benzene. This material is normallyconsidered to be a non-solvent for lignin.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100 ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of xylene. While this mixture is being stirred, add25 ml. (0.25 parts) of 80% acetic acid slowly over a five minuteinterval. As soon as the viscosity of the mixture starts to increase thestirring may be discontinued and a layer starts to form which containsthe lignin.

EXAMPLE 76

This example illustrates the separation of lignin from kraft blackliquor by using ethyl benzene, an aromatic hydrocarbon. This material isnormally considered to be a non-solvent for lignin.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100 ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of ethyl benzene. While this mixture is beingstirred, add 25 ml. (0.25 parts) of 80% acetic acid slowly over a fiveminute interval. As soon as the viscosity of the mixture starts toincrease the stirring may be discontinued and a layer starts to formwhich contains the lignin.

EXAMPLE 77

This example illustrates the separation of lignin from kraft blackliquor by using monochlorobenzene, an aromatic chlorohydrocarbon. Thismaterial is normally considered to be a non-solvent for lignin.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100 ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of monochlorobenzene. While this mixture is beingstirred, add 25 ml. (0.25 parts) of 80% acetic acid slowly over a fiveminute interval. As soon as the viscosity of the mixture starts toincrease the stirring may be discontinued and a layer starts to formwhich contains the lignin.

EXAMPLE 78

This example illustrates the separation of lignin from kraft blackliquor by using a number one fuel oil, which is an aliphatichydrocarbon. This material is normally considered to be a non-solventfor lignin.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100 ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of number one fuel oil. While this mixture is beingstirred, add 25 ml. (0.25 parts) of 80% acetic acid slowly over a fiveminute interval. As soon as the viscosity of the mixture starts toincrease the stirring may be discontinued and a layer starts to formwhich contains the lignin.

EXAMPLE 79

This example illustrates the separation of lignin from kraft blackliquor by using Freon TF, a duPont product, which is a fluorocarbon.This material is normally considered to be a non-solvent for lignin. Theuse of fluorocarbons have several advantages, the first is that theyhave low boiling points which requires less energy to spray-dry and theycan easily be recovered and used again. These types of materials alsoare non-flammable and relatively non-toxic.

PROCEDURE: Charge 400 ml. (4 parts) of kraft black liquor (50% solids)into a one liter vessel. Add 100 ml. (1 part) of water and stir. Thenadd 100 ml. (1 part) of Freon TF, a fluorocarbon. While this mixture isbeing stirred, add 25 ml. (0.25 parts) of 80% acetic acid slowly over afive minute interval. As soon as the viscosity of the mixture starts toincrease the stirring may be discontinued and a layer starts to formwhich contains the lignin.

EXAMPLE 80

This example illustrates the separation of lignin from sulfite wasteliquor by using a solvent such as methyl amyl ketone, an organic ketone.

PROCEDURE: Charge 320 ml. (3.2 parts) of sulfite waste liquor into a oneliter vessel. Add 220 ml. (2.2 parts) of water and stir. Then add 200ml. (2.0 parts) of methyl amyl ketone. While this mixture is beingstirred, add 50 ml. (0.5 parts) of concentrated sulfuric acid slowlyover a five minute interval. Once the addition of the sulfuric acid iscomplete, the stirring may be continued for another fifteen minutes andthen stopped. The length of time which is required at this point forstirring is dependent on the amounts of material involved in theseparation. Once the stirring is discontinued, a layer starts to formwhich contains the lignin.

EXAMPLE 81

This example illustrates the separation of lignin from sulfite wasteliquor by using a solvent such as benzaldehyde, an aromatic aldehyde.

PROCEDURE: Charge 320 ml. (3.2 parts) of sulfite waste liquor into a oneliter vessel. Add 220 ml. (2.2 parts) of water and stir. Then add 200ml. (2.0 parts) of benzaldehyde. While this mixture is being stirred,add 50 ml. (0.5 parts) of concentrated sulfuric acid slowly over a fiveminute interval. Once the addition of the sulfuric acid is complete, thestirring may be continued for another fifteen minutes and then stopped.The length of time which is required at this point for stirring isdependent on the amounts of material involved in the separation. Oncethe stirring is discontinued, a layer starts to form which contains thelignin.

EXAMPLE 82

This example illustrates the separation of lignin from sulfite wasteliquor by using mesityl oxide, an organic ketone. This material isnormally considered to be only a partial solvent for lignin.

PROCEDURE: Charge 320 ml. (3.2 parts) of sulfite waste liquor into a oneliter vessel. Add 220 ml. (2.2 parts) of water and stir. Then add 200ml. (2.0 parts) of mesityl oxide. While this mixture is being stirred,add 50 ml. (0.5 parts) of concentrated sulfuric acid slowly over a fiveminute interval. Once the addition of the sulfuric acid is complete, thestirring may be continued for another fifteen minutes and then stopped.The length of time which is required at this point for stirring isdependent on the amounts of material involved in the separation. Oncethe stirring is discontinued, a layer starts to form which contains thelignin.

EXAMPLE 83

This example illustrates the separation of lignin from sulfite wasteliquor by using butyraldehyde, an organic aldehyde. This material isnormally considered to be only a partial solvent for lignin.

PROCEDURE: Charge 320 ml. (3.2 parts) of sulfite waste liquor into a oneliter vessel. Add 220 ml. (2.2 parts) of water and stir. Then add 200ml. (2.0 parts) of butyraldehyde. While this mixture is being stirred,add 50 ml. (0.5 parts) of concentrated sulfuric acid slowly over a fiveminute interval. Once the addition of the sulfuric acid is complete, thestirring may be continued for another fifteen minutes and then stopped.The length of time which is required at this point for stirring isdependent on the amounts of material involved in the separation. Oncethe stirring is discontinued, a layer starts to form which contains thelignin.

EXAMPLE 84

This example illustrates the separation of lignin from sulfite wasteliquor by using a xylene solvent which consists of a mixture of orthoand para xylene as well as some ethyl benzene, which represent aromatichydrocarbons. This material is normally considered to be a non-solventfor lignin.

PROCEDURE: Charge 320 ml. (3.2 parts) of sulfite waste liquor into a oneliter vessel. Add 220 ml. (2.2 parts) of water and stir. Then add 200ml. (2.0 parts) of a xylene solvent which consists of a mixture of orthoand para xylene as well as some ethyl benzene. While this mixture isbeing stirred, add 50 ml. (0.5 parts) of concentrated sulfuric acidslowly over a five minute interval. Once the addition of the sulfuricacid is complete, the stirring may be continued for another fifteenminutes and then stopped. The length of time which is required at thispoint for stirring is dependent on the amounts of material involved inthe separation. Once the stirring is discontinued, a layer starts toform which contains the lignin.

EXAMPLE 85

This example illustrates the separation of lignin from sulfite wasteliquor by using a Freon TF, a duPont product which is a fluorocarbon.This material is (continuation of Example 85) normally considered to bea non-solvent for lignin.

PROCEDURE: Charge 320 ml. (3.2 parts) of sulfite waste liquor into a oneliter vessel. Add 220 ml. (2.2 parts) of water and stir. Then add 200ml. (2.0 parts) of Freon TF, a fluorocarbon. While this mixture is beingstirred, add 50 ml. (0.5 parts) of concentrated sulfuric acid slowlyover a five minute interval. Once the addition of the sulfuric acid iscomplete, the stirring may be continued for another fifteen minutes andthen stopped. The length of time which is required at this point forstirring is dependent on the amounts of material involved in theseparation. Once the stirring is discontinued, a layer starts to formwhich contains the lignin.

CONCLUSION

It will be apparent from the above that a new and unique process hasbeen disclosed for separating lignin from waste black cooking liquorresulting from the kraft and sulfite paper pulping processes and thenproducing an expoxide-lignin resin from the so separated lignin. Thisresin is then susceptible of many uses including adhesives, paints andcast and hardened resinous or plastic products. This process thereforeprovides new use for lignin which has been previously used primarilyonly for its heat value by burning. It will be clear from the presentdisclosure that lignin resulting from paper pulping processes in generalmay be utilized for the disclosed purposes and it need not have beenseparated solely by the process first disclosed herein. The ligninseparated from the black liquors is also suscpetible of many commercialuses.

Although this invention has been described in its preferred form andpreferred practice with a certain degree of particularity, it isunderstood that the present disclosure of the preferred form andpreferred practice has been made only by way of example and thatnumerous changes in the details of construction and the combination andarrangement of parts and steps may be resorted to without departing fromthe spirit and the scope of the invention as hereinafter claimed.

What is claimed is:
 1. The method of producing unsaturated reactive endgroups on lignin obtained by contacting aqueous waste black liquor fromthe kraft pulping process with an organic chemical solvent, and addingan acid to the mixture to lower the pH to thereby separate a layer whichlayer contains extracted or separated lignin in said organic solventseparate from an aqueous layer, wherein such method comprises eitherreacting the said separated layer of lignin in said organic solvent witha carbonyl compound containing active hydrogen and a compound selectedfrom the group consisting of alpha, beta-unsaturated carbonyl compoundsand acrylonitrile, or reacting said lignin in said organic solvent witha compound selected from the group consisting of cyanoacetic acid,esters of cyanoacetic acid, malonic acid and esters of malonic acid, toproduce alpha, beta-unsaturated reactive end groups on said lignin whichend groups are amenable to epoxidation.
 2. The method of claim 1,wherein said reactive end groups are unsaturated carbonyl groups.
 3. Themethod of claim 1, wherein said reactive end groups are unsaturatednitrogen containing compounds.
 4. The method of claim 2, wherein saidreactive unsaturated carbonyl groups comprise aldehydes, ketones, estersor acids.
 5. The method of claim 3, wherein said reactive unsaturatednitrogen containing compounds comprise nitriles or amides.
 6. The methodof claim 1, wherein the lignin containing alpha, beta-unsaturatedreactive end groups is epoxidized by the reaction with a peroxide. 7.The method of claim 1, wherein the lignin containing alpha,beta-unsaturated reactive end groups is epoxidized by the reaction withhydrogen peroxide or sodium peroxide.
 8. The method of claim 2, whereinthe lignin containing alpha, beta-unsaturated carbonyl groups isepoxidized by the reaction with a peroxide.
 9. The method of claim 2,wherein the lignin containing alpha, beta-unsaturated reactive endgroups is epoxidized by the reaction with hydrogen peroxide or sodiumperoxide.
 10. The method of claim 3, wherein the lignin containingalpha, beta-unsaturated nitrogen containing end groups is epoxidized bythe reaction with a peroxide.
 11. The method of claim 3, wherein thelignin containing alpha, beta-unsaturated reactive end groups isepoxidized by the reaction with hydrogen peroxide or sodium peroxide.12. The method of making a lignin-epoxide material comprising the stepsof placing lignin in a liquid medium, reacting said lignin with acompound selected from the group consisting of alpha, beta-unsaturatedcarbonyl compounds, acrylonitrile, cyanoacetic acid, esters ofcyanoacetic acid, malonic acid, and esters of malonic acid, to producealpha, beta-unsaturated end groups on the lignin molecules which endgroups are selected from the group consisting of alpha, beta-unsaturatedcarbonyl groups and alpha, beta-unsaturated nitrogen containingcompounds, and, thereafter, converting the alpha, beta-unsaturatedcarbon-carbon bonds of said unsaturated end groups to epoxides, oroxirane compounds, by reaction with a peroxide.
 13. The method claimedin claim 12, wherein said lignin is recovered from the waste blackcooking liquor from the kraft paper pulping process.
 14. The methodclaimed in claim 13, wherein said liquid medium is an aqueous medium oran organic solvent for said lignin.
 15. The method claimed in claim 14,wherein said unsaturated carbonyl groups comprise aldehydes, ketones,esters or acids.
 16. The method claimed in claim 14, wherein saidunsaturated nitrogen containing compounds comprise nitriles or amides.17. The method claimed in claim 14, wherein said peroxide is hydrogenperoxide or sodium peroxide.
 18. The method claimed in claim 15, whereinsaid unsaturated carbonyl groups are produced by the reaction of mesityloxide and formaldehyde with the lignin; by the reaction of acrolein withthe lignin; by the reaction of malonic acid with the lignin; by thereaction of dimethylmalonate with lignin; or by the reaction ofdiethylmalonate with the lignin.
 19. The method claimed in claim 16,wherein said unsaturated nitrogen containing compounds are produced bythe reaction of acrylonitrile, cyanoacetic acid, ethyl cyanoacetic andmethyl cyanoacetic.
 20. The method of making a lignin-epoxide materialcomprising the steps of placing lignin in a liquid medium, reacting saidlignin with a compound selected from the group consisting of alpha,beta-unsaturated carbonyl compounds, acrylonitrile, cyanoacetic acid,esters of cyanoacetic acid, malonic acid, and esters of malonic acid, toproduce alpha, beta-unsaturated end groups on the lignin molecules whichend groups are selected from the group consisting of alpha,beta-unsaturated carbonyl groups and alpha, beta-unsaturatednitrogen-containing compounds, and thereafter converting the said alpha,beta-unsaturated carbon-carbon bonds of said unsaturated end groups toepoxides, or oxirane compounds, by reaction with active oxygen agents.21. The method of making a lignin-epoxide material comprising the stepsof placing lignin in a liquid medium, reacting said lignin with acompound selected from the group consisting of alpha, beta-unsaturatedcarbonyl compounds, acrylonitrile, cyanoacetic acid, esters ofcyanoacetic acid, malonic acid, and esters of malonic acid, to producealpha, beta-unsaturated end groups on the lignin molecules which endgroups are selected from the group consisting of alpha, beta-unsaturatedcarbonyl groups and alpha, beta-unsaturated nitrogen containingcompounds, and thereafter converting the said alpha, beta-unsaturatedcarbon-carbon bonds of said unsaturated end groups to epoxides, oroxirane compounds, by reaction with hydrogen peroxide or sodiumperoxide.
 22. Lignin derivatives comprising lignins with alpha,beta-unsaturated carbonyl end groups thereon.
 23. Lignin derivativescomprising lignins with alpha, beta-unsaturated nitrogen-containing endgroups thereon.
 24. Lignin-epoxide compounds comprising ligninscontaining oxirane rings in end groups thereon, and in which saidoxirane rings are the product of the peroxidization of alpha,beta-unsaturated carbon-carbon bonds contained in said end groups.